This invention relates to induction heating apparatus.
Cooking hobs are known which comprise one or more large induction coils, on which pans having an electrically inductive base can be stood. In use, a high frequency signal (in excess of 20 kHz) is applied to the coil, which generates a magnetic field that induces eddy currents in the pan base. The base of the pan is not an ideal conductor, and thus the electrical energy is dissipated as heat as current flows through the pan base. Thus, the heating effect is proportional to I.sup.2 R, where I is the current in the base of the pan and R is the electrical resistance of the pan.
The resistivity of the pan base depends on the material that it is made from. Thus, it will be appreciated that the temperature which the pan base reaches will be dependent on the material of the pan, with the obvious disadvantage that discrepancies will occur between the heat setting, which has been selected by the user, and the actual heat developed.